The SN2 reaction mechanism is well known in the art. The shorthand SN2 means substitutions nucleophilic, bimolecular, which indicates that a nucleophile (Nuc) displaces a leaving group (LG) at a tetrahedral carbon center leading to an inversion of stereochemistry (Walden inversion). The general scheme can be depicted as follows:

The SN2 reaction is ubiquitous in the art due to its general utility. Many substituents on commonly synthesized compounds, including pharmaceuticals, diagnostic compounds, fungicides, bacteriocides, virucides, etc. possess one or more function groups that can be envisioned as nucleophiles in the SN2 reaction.
Exemplary nucleophiles that are known in the art include halides (e.g. F, Cl, Br and I), cyanide (CN), azide (N3), nitride, etc. While many compounds having such groups are known, it is often the case that starting materials having easily displaceable leaving groups are hard to come by.
One class of starting materials that is difficult to substitute with a nucleophile, but which would be expected to provide a rich source of starting materials, includes alcohols. Alcohols are ubiquitous in nature. From methanol and ethanol, which are commonly produced by fermentation of sugars to sugars themselves (both simple and complex), there is a wide variety of alcohols that could be converted to their corresponding halides, azides, nitrides and cyanides. However, it has been difficult to convert alcohols to halides, azides and cyanides (amongst others), by the SN2 pathway, as the OH group of alcohols is a strong base and thus a poor leaving group for nucleophilic substitution.
It is known to prepare aryl sulfonates of hydroxyl-bearing compounds and aryl sulfonate esters of benzene sulfonic acids (such as tosylates) have been used with great advantage to make a variety of compounds wherein the hydroxyl groups are displaced by nucleophiles, such as halides, azides and cyanides. However, there are still situations in which the reaction kinetics are unfavorable for using such reagents to prepare compounds in which an alcohol has been replaced by a nucleophile. Furthermore, nucleophiles often react with substrates containing an leaving group in unintended ways leading to unwanted side products.                There is a need for leaving groups that can be displaced by nucleophiles in high yields and in a timely fashion.        There is a need for leaving groups that are selective for a given cation of a nucleophilic salt thereby promoting an SN2 reaction involving the nucleophilic salt to occur at the intended site on the substrate.        There is a need for selective and rapid-reacting leaving groups that are attached to an insoluble support to allow for the facilitate separation of the these leaving groups from the desired products by filtration        There is a further need for reagents that can be used to synthesize such leaving groups.        There is a further need for methods of using said reagents to prepare chemical entities containing such leaving groups.        There is further a need for methods of making target compounds containing a desired nucleophile as part of its structure from starting materials, wherein the starting materials have leaving groups that are easily displaced by SN2-type reaction.                    These and other needs are met by embodiments of the present invention.                        